Ultra-short wave radio system



Sept. 7, 1937.

H. E. HOLLMANN 2,092,069 ULTRA SHORT WAVE RADIO SYSTEM Filed Aug. 7,1936 INS ULAT/ON INVIENTOR HANS ERICH HOLLMANN' Patented Sept. 7, 1937UNITED STATES PATENT OFFICE Application August 7, In Germany avoidinginterlong-wave oscillations.

It is appreciated by those skilled in the art that the circuitarrangements which have proved the most satisfactory for use inultra-short wave of the triode discharge tube still holds first placeeither as an ultra-high frequency oscillation generator, or as adetector.

The object of my invention is primarily to pro- 15 vide an ultra-highfrequency circuit having means, for facilitating the adjustment of thefeed-back. Other objects and advantages will become apparent as theinvention is further elucidated.

In describing my invention reference will be made to the accompanyingdrawing in which,

Figure 1 shows diagrammatically the type of circuit to which .myinvention relates,

,Figure 2 shows more in detail the construc- 25 tional details of oneembodiment of my invention,

Figure 3 shows a cross section along the line 3-3 of Fig. 2, and

Figure 4 shows a modification as applied to a push-pull circuit.

Referring to Fig. 1, an electron discharge tube R is provided with theusual cathode 5, anode control electrode and the cathode,

The anode-to-cathode circuit preferably includes a variable tap A on theinductive loop L, a utilization device In a receiver, the utilizationdevice may be p either a telephone head-set or a transformer feeding toan intermediate frequency amplifier. In an oscillation generator anysuitable load may be coupled to the output circuit.

By shifting the position of the tap A, the highfrequency potentialcomponents for grid and plate are varied, and the feed-back factor isvaried as well. Thus the critical point between a non-oscillating and anoscillating condition adjustments of the circuit can be madeaccordingly. The vari- 1936, Serial No. 94,724 June 8, 1935 able tap Ais conveniently pivoted at the center of the ring-shaped loop L so as tocontact therewith throughout a. wide arc.

The circuit thus far described is not ideal for ultra high frequencyoperation since an undesirable inductive reaction takes place betweenthe oscillatory loop and adjacent portions of the anode supply lead,including the movable tap A and the conductive arm on which the tap ismounted. Accordingly, I have found it possible to considerably improveby mounting the discharge tube and the oscillatory loop L within anopening or recess out out from a metallic plate, which may be steel, ifdesired.

Referring to Fig. 2, the discharge tube A is therein shown within and toone, side of an opening l1 in the thick metal plate E. The inductiveloop L is mounted concentric with the opening I l. The contact arm A issupported in any suitable manner (not shown) and has its pivot centerconcentric with the loop L. A contact plate i9 is mounted in" a recessin the plate E and is insulated therefrom by an insulator 2i. Thisinsulator extends beneath the contact plate l9 and is sufficiently thin.to form a suitable dielectric, whereby the contact plate l9 and theportion of the plate E may act asa coupling condenser for grounding theradio frequency currents in the loop L where contact is made therewithby the contact arm A. This contact arm is preferably resilient andengages conductively with the contact plate l9.

By virtue of the constructional features just described it is foundpossibleto maintain an ultrahigh frequency potential node on the loop Lat or near position of contact with the contact arm A. Furthermore, thefeed-back of energy may readily be controlled by moving the arm A to oneside or the other of this nodal point. The coupling arrangement betweenthe plate E may also be seen to afford a very short path for ultra highfrequencies, this being of very great advantage in making suitableadjustments for operating the system on any desired carrier wave in theultra-short wave spectrum. The output circuit shown in Fig. 1 will beunderstood to include the contact plate I 9 of Figs. 2 and 3. Theinsulator 2| protects the direct current source l3 from beingshort-circuited-since the positive terminal thereof leads through theutilization device H to the contact plate l9 while the negative terminalof the source l3 leads to the cathode which is also grounded at onepoint through the metal plate E.

The cross sectional view of Fig. 3 when considered with the plan view ofFig. 2 shows further constructional features. tact arm A may be mountedupon a spindle 23 pivoted in any suitable manner (not shown) and thecircuit arrangements loop L and the grouncl ng For example, theconprovided with a grid bias resistor W may be connected between theplate E and that portion of the loop L which interconnects the grid 9and one terminal of the capacitor C.

Referring to Fig. 4, I show a modification of the invention in which twodischarge tubes R1 and R2 are provided for push-pull operation. In thiscase the tubes are inserted in an opening in the plate E1 in such manneras to accommodate also twoinductiive loops La and Lg.. The loop Laextends between the two anodes while the loop Lg extends between the twogrids respectively of the tubes R1 and R2.

In this embodiment provision is made for grounding the loop L9. at radiofrequency potentials through the contact arm A and the contact plate IS,the same as in Fig. 2. Furthermore, the grid biasing lead through theloop Lg may be connected to the cathodes by means of a contact arm A1having the grid bias resistor W1 mounted thereon for introducing asuitable impedance between the loop Lg and the plate E1 to which thecathodes are connected at one point.-

' It will be seen from observation of Fig. 3 that two oscillatingcircuits La CB and Lg Cg are provided where the capacitor C9. isparallel connected across the loop La between the two anodes and wherethe capacitor C1; is parallel connected across the loop Lg between thetwo grids. Also in this case provision is made for shifting thegrounding points at will according to the adjustment of the contact armsA and A1.

In the embodiment shown in Fig. 4 as well as that of Fig. 2 the platesupply lead is connected to the contact plate l9 and thus not only thecontinuous excitation of oscillations can be adjusted at will, but alsosymmetry of the circuit arrangement can be exactly balanced.

A still further modification of my invention may be made in the one casein reference to the apparatus shown in Fig. 2 and in the other case inrespect to the apparatus shown-in Fig. 4 ii the contact plate l9 andinsulator 2| are eliminated and the contact arm A is permitted toestablish connection between the loop L- (or La) and the metal plate E(RE1) In this case however, the cathode could not be grounded but theentire plate E would be charged at the high plate potential. Thenecessity for suitably insulating the cathode leads from the plate Eintroduces practical diiiiculties which cause t 'e arrangements firstdescribed to be preferred.

In the embodiment shown it is assumed that the inductive loops aresituated in the plane of the metallic plateE or E1. The inductive loopsmay, however, be disposed in front of or in the rear of the metallicplate ifso desired but should be maintained essentially in ajplaneparallel to the plane of the grounding plate E.

I claim:'

1. In a radio circuit of the class described, an electron discharge tubehaving a cathode, an anode and a control grid, an inductive loop and acapacitor constituting a resonant means for intercoupling the anode andcontrol grid, a biasing resistor connected between the cathode andcontrol grid,a source of direct current potential and a utilizationdevice connected between the cathode and anode, a metallic member havingan opening therein sufliciently large to accommodate said discharge tubeand said inductive loop, a contact plate insuiatingly mounted on saidmetallic discharge tube arrangement the cathode,

manual control knob 25. The

member adjacent said opening, a contact arm pivotally mounted at thecenter of said inductive loop and adapted to slidably contact bothwithsaid loop and with said contact plate, said contact arm and said contactplate being in circuit between said anode and said source of directcurrent potential.

2. Apparatus according to claim 1 and having means including adielectric element between said metallic member and said contact platefor electrostatically coupling said contact arm to said metallic memberat ultra high frequencies.

3. In an ultra short wave system, an electron having a grid-tocathodeinput circuit including a bias resistor; a cathode-to-anode circuitincluding a source of anode potential and a utilization device; shieldinmeans comprising a thick flat metallic plate having an opening thereinarrangement, said opening being of circular outline for at least aportion thereof; a capacitor; an inductive loop serially connected fromthe anode of said discharge tube arrangement through said capacitorcharge tube arrangement and forming a resonant circuit, said loop beingconcentric with the opening in said shielding means; and feed-backadjusting means in circuit between saidutilization device and said loop,the last said means constituting a contact plate and an adjustablecontact for accommodating said to the grid of said disarm pivoted at thegeometric center of said loop metallic plate surrounding and shieldingsaid arrangement, a contact segment insulatinglymounted in electrostaticassociation with a recessed portion of said plate, an inductive loopconnected to the anode portion of said electron discharge arrangement,and means including a rotatable contact arm for adjustably bridging theinductive loop and the contact segment.

5. A push-pull electron discharge tube arrangement according to claim 4and having two electron discharge tubes of the triode type, the anodesof said'tubes being interconnected by said inductive loop, a secondinductive loop disposed within the orifice of said plate andinterconnecting the control grids 0! said tubes, and means including asecond rotatable contact arm having a grid leak resistor interconnec inginner' and outer contact elements, for providing an adjustable leakagepath between the control grids and said metallic plate.

6. In an ultra-high frequency regenerative circuit arrangement, atriodeelectrondischarge tube having an anode, a cathode and acontrolgrid, an inductive loop and a capacitor interconnecting saidanode and control grid, a grounded conductive medium shieldingandsurroundingthe zone in which said loop lies, a source 01 potentialfor rendering said anode positive with respect to said source beingconnected at a suitable point along the arc of said loop, a rotatablecontactor arm through which said potential is applied to said loop, andan arcuately formed plate disposed in a recessed portion of saidsurrounding conductive medium and in electrostatic associationtherewith, said plate being in contact with a portion or said rotatablearm.

HANS ERICK ROMA CERTIFICATE OF CORRECTION. Patent No. 2,092,069.September 7, 19 7.

I HANS ERICH HOLLHANN.

It is hereby oertifi'ed that the above numbered patent was erroneouslyissued to the inventor, said "HCBLLMANN" whereas said patent should havebeen issued to Telefunken Gesellschaft fflr' Drahtlose Telegraphie m. bH. Berlin, Germany, a corporation of Germany, v as shown by the recordof assignments .in this off-lee; and that the said Letters Patent shouldbe read with this correction therein that the same may conform to therec- 6rd of the case in the Patent Office.

Signed andesealed this 10th day of January, A. D. 1939.

a I Henry Va n Ars dale (Seal) f Acting Commissioner of Patents.

v CERTIFICATE 0 commcnon. 7 Patent No; 2,092,069. September 7, 1937.

mus ERICH HOLLHANN.

It is hereby cer'tifiediflaat the above numbered patent was erroneouslyissued to the inventor, said "HoLLMANN" :whereas' said patent shouldhave been issued to Telefunken Gesell schaft fflr DrahtloseTelegraphi'e' m. b.

H., Berlin, Germany, acorporation of Germany) as shown by the record ofassignments .in this off-ice; and that the said Letters Patent should beread with this correction therein that the same may conform to the rec-6rd of the case in the Patent Office.

Signed andtsealed this 10th day of January, A. D. 1959.

. Henry Van Ars dale -($ee.l) f Acting Commissioner of Patents.

